Monday, July 5, 2010

Linux and Linux Device driver interview questions

Linux is one of the very common Operating Systems and hope many would like to have some linux interview questions for their interview. Here is a collection of questions for linux and linux device driver related interviews :-) All the Best !

1. What is the difference in features between kernel 2.2, 2.4 and 2.6 ?
2. What are Static and Shared libraries ?
3. What is dynamic linking ? What is static linking ?
4. What are the advantages of Dynamic linking or Shared libraries ?
5. Does gcc search for both static and shared libraries ? Which is searched initially by gcc compiler ?
6. What should be done for Shared library based linking in gcc ?
7. What should be done for static library based linking in gcc ?
8. What is object file and what are symbols ?
9. Can you tell the memory layout based on Data,BSS,HEAP and STACK ?
10. What are the ways in which linux kernel can be compiled ?
11. How will get the driver added into the kernel ? What are Kconfig files ?
12. What is a kernel module ?
13. What is the difference between insmod and modprobe ?
14. How will you list the modules ?
15. How do you get the list of currently available drivers ?
16. How will you Access userspace memory from kernel ? What are the various methods ?
17. What is the use of ioctl(inode,file,cmd,arg) ApI ?
18. What is the use of the poll(file, polltable) API ?
19. What is the use of file->private_data in a device driver structure ?
20. What is a device number ?
21. What are the two types of devices drivers from VFS point of view ?
22. What are character devices ?
23. How does the character device driver adds and remove itself from the kernel ?
What is the use of register_chrdev and unregister_chrdev ?
24. What is the role of interrupts in a device driver ? How are interrupts handled in device driver ?
25. How will you make interrupt handlers as fast as possible ?
26. What are the types of softirqs ?
27. Difference between Timer Softirq and Tasklet Softirq ?
28. What are tasklets ? How are they activated ? when and How are they initialized ?
29. What is task_struct and how are task states maintained ?
30. What is rwlock and spinlock ? Briefly explain about both of them ?
31. When will you use rwlock instead of spinlock ?
32. Can spinlock/rwlock be used in Interrupt handler ?
33. Tell about the Memory Layout of a Process in Linux .
34. How will you trace the system calls made into the kernel of lInux ?
35. What is mmap ? MMAP & malloc ? MMAP & brk ? MMAP adv & dis-adv.
36. Tell the relation between Malloc and MMAP
37. Advantages of MMAP over Read ?
38. Tell the role of brk() in malloc / Tell the relation between heap and brk?
39. Example of using MMAP and MUNMAP in C ?
40. Tell about the method/steps in Linux Kernel Compilation.
41. What is Kmalloc and how does it differ from normal malloc ? or Why can't we use malloc in kernel code ?
42. What happens as soon as a packet arrives from the network in Linux ?
43. What is a stack frame, stack pointer & frame pointer ?
44. What is a profiler ? Which one have you used ?
45. How do you determine the direction of stack growth ?

7 comments:

  1. It will be really helpful if you can post the answers as well... Thanks in advance... :)

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  3. please provide these questions efficeant answars with explanation please

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